Re: first google adwords campaign

It also depends upon your daily budget. You are going to target many countries and locations within a country.Although this is always a good practice to create separate campaigns for different country/location, to gauge and optimize the campaign performance easily. But if you are not willing to spend a huge budget in the beginning, Just create a single campaign and add multiple cities/countries as your targeted area; less time consuming and less effort

Later, when you get sufficient performance data, you can download geographic & location report to take further decisions!